public final void readFields(DataInput in) throws IOException {
metadata.clear();
int sizeOrVersion = in.readInt();
if (sizeOrVersion < 0) { // version
version = sizeOrVersion;
switch (version) {
case VERSION:
url = Text.readString(in);
base = Text.readString(in);
content = new byte[in.readInt()];
in.readFully(content);
contentType = Text.readString(in);
metadata.readFields(in);
break;
default:
throw new VersionMismatchException((byte) VERSION, (byte) version);
}
} else { // size
byte[] compressed = new byte[sizeOrVersion];
in.readFully(compressed, 0, compressed.length);
ByteArrayInputStream deflated = new ByteArrayInputStream(compressed);
DataInput inflater = new DataInputStream(new InflaterInputStream(deflated));
readFieldsCompressed(inflater);
}
}
public final void write(DataOutput out) throws IOException {
Text.writeString(out, id); // write url
out.writeInt(content.length); // write content
out.write(content);
Text.writeString(out, contentType); // write contentType
metadata.write(out); // write metadata
}
public final void write(DataOutput out) throws IOException {
out.writeInt(VERSION);
Text.writeString(out, url); // write url
Text.writeString(out, base); // write base
out.writeInt(content.length); // write content
out.write(content);
Text.writeString(out, contentType); // write contentType
metadata.write(out); // write metadata
}
private final void readFieldsCompressed(DataInput in) throws IOException {
byte oldVersion = in.readByte();
switch (oldVersion) {
case 0:
case 1:
url = UTF8.readString(in); // read url
base = UTF8.readString(in); // read base
content = new byte[in.readInt()]; // read content
in.readFully(content);
contentType = UTF8.readString(in); // read contentType
// reconstruct metadata
int keySize = in.readInt();
String key;
for (int i = 0; i < keySize; i++) {
key = UTF8.readString(in);
int valueSize = in.readInt();
for (int j = 0; j < valueSize; j++) {
metadata.add(key, UTF8.readString(in));
}
}
break;
case 2:
url = Text.readString(in); // read url
base = Text.readString(in); // read base
content = new byte[in.readInt()]; // read content
in.readFully(content);
contentType = Text.readString(in); // read contentType
metadata.readFields(in); // read meta data
break;
default:
throw new VersionMismatchException((byte) 2, oldVersion);
}
}
private ParseStatus output(
Text key,
CrawlDatum datum,
Content content,
ProtocolStatus pstatus,
int status,
int outlinkDepth) {
datum.setStatus(status);
datum.setFetchTime(System.currentTimeMillis());
if (pstatus != null) datum.getMetaData().put(Nutch.WRITABLE_PROTO_STATUS_KEY, pstatus);
ParseResult parseResult = null;
if (content != null) {
Metadata metadata = content.getMetadata();
// store the guessed content type in the crawldatum
if (content.getContentType() != null)
datum
.getMetaData()
.put(new Text(Metadata.CONTENT_TYPE), new Text(content.getContentType()));
// add segment to metadata
metadata.set(Nutch.SEGMENT_NAME_KEY, segmentName);
// add score to content metadata so that ParseSegment can pick it up.
try {
scfilters.passScoreBeforeParsing(key, datum, content);
} catch (Exception e) {
if (LOG.isWarnEnabled()) {
LOG.warn("Couldn't pass score, url " + key + " (" + e + ")");
}
}
/*
* Note: Fetcher will only follow meta-redirects coming from the
* original URL.
*/
if (parsing && status == CrawlDatum.STATUS_FETCH_SUCCESS) {
if (!skipTruncated || (skipTruncated && !ParseSegment.isTruncated(content))) {
try {
parseResult = this.parseUtil.parse(content);
} catch (Exception e) {
LOG.warn("Error parsing: " + key + ": " + StringUtils.stringifyException(e));
}
}
if (parseResult == null) {
byte[] signature =
SignatureFactory.getSignature(conf)
.calculate(content, new ParseStatus().getEmptyParse(conf));
datum.setSignature(signature);
}
}
/*
* Store status code in content So we can read this value during parsing
* (as a separate job) and decide to parse or not.
*/
content.getMetadata().add(Nutch.FETCH_STATUS_KEY, Integer.toString(status));
}
try {
output.collect(key, new NutchWritable(datum));
if (content != null && storingContent) output.collect(key, new NutchWritable(content));
if (parseResult != null) {
for (Entry<Text, Parse> entry : parseResult) {
Text url = entry.getKey();
Parse parse = entry.getValue();
ParseStatus parseStatus = parse.getData().getStatus();
ParseData parseData = parse.getData();
if (!parseStatus.isSuccess()) {
LOG.warn("Error parsing: " + key + ": " + parseStatus);
parse = parseStatus.getEmptyParse(conf);
}
// Calculate page signature. For non-parsing fetchers this will
// be done in ParseSegment
byte[] signature = SignatureFactory.getSignature(conf).calculate(content, parse);
// Ensure segment name and score are in parseData metadata
parseData.getContentMeta().set(Nutch.SEGMENT_NAME_KEY, segmentName);
parseData.getContentMeta().set(Nutch.SIGNATURE_KEY, StringUtil.toHexString(signature));
// Pass fetch time to content meta
parseData.getContentMeta().set(Nutch.FETCH_TIME_KEY, Long.toString(datum.getFetchTime()));
if (url.equals(key)) datum.setSignature(signature);
try {
scfilters.passScoreAfterParsing(url, content, parse);
} catch (Exception e) {
if (LOG.isWarnEnabled()) {
LOG.warn("Couldn't pass score, url " + key + " (" + e + ")");
}
}
String origin = null;
// collect outlinks for subsequent db update
Outlink[] links = parseData.getOutlinks();
int outlinksToStore = Math.min(maxOutlinks, links.length);
if (ignoreExternalLinks || ignoreInternalLinks) {
URL originURL = new URL(url.toString());
// based on domain?
if ("bydomain".equalsIgnoreCase(ignoreExternalLinksMode)) {
origin = URLUtil.getDomainName(originURL).toLowerCase();
}
// use host
else {
origin = originURL.getHost().toLowerCase();
}
}
// used by fetchNode
if (fetchNode != null) {
fetchNode.setOutlinks(links);
fetchNode.setTitle(parseData.getTitle());
FetchNodeDb.getInstance().put(fetchNode.getUrl().toString(), fetchNode);
}
int validCount = 0;
// Process all outlinks, normalize, filter and deduplicate
List<Outlink> outlinkList = new ArrayList<Outlink>(outlinksToStore);
HashSet<String> outlinks = new HashSet<String>(outlinksToStore);
for (int i = 0; i < links.length && validCount < outlinksToStore; i++) {
String toUrl = links[i].getToUrl();
toUrl =
ParseOutputFormat.filterNormalize(
url.toString(),
toUrl,
origin,
ignoreInternalLinks,
ignoreExternalLinks,
ignoreExternalLinksMode,
urlFilters,
urlExemptionFilters,
normalizers);
if (toUrl == null) {
continue;
}
validCount++;
links[i].setUrl(toUrl);
outlinkList.add(links[i]);
outlinks.add(toUrl);
}
// Only process depth N outlinks
if (maxOutlinkDepth > 0 && outlinkDepth < maxOutlinkDepth) {
reporter.incrCounter("FetcherOutlinks", "outlinks_detected", outlinks.size());
// Counter to limit num outlinks to follow per page
int outlinkCounter = 0;
// Calculate variable number of outlinks by depth using the
// divisor (outlinks = Math.floor(divisor / depth * num.links))
int maxOutlinksByDepth =
(int)
Math.floor(outlinksDepthDivisor / (outlinkDepth + 1) * maxOutlinkDepthNumLinks);
String followUrl;
// Walk over the outlinks and add as new FetchItem to the queues
Iterator<String> iter = outlinks.iterator();
while (iter.hasNext() && outlinkCounter < maxOutlinkDepthNumLinks) {
followUrl = iter.next();
// Check whether we'll follow external outlinks
if (outlinksIgnoreExternal) {
if (!URLUtil.getHost(url.toString()).equals(URLUtil.getHost(followUrl))) {
continue;
}
}
reporter.incrCounter("FetcherOutlinks", "outlinks_following", 1);
// Create new FetchItem with depth incremented
FetchItem fit =
FetchItem.create(
new Text(followUrl),
new CrawlDatum(CrawlDatum.STATUS_LINKED, interval),
queueMode,
outlinkDepth + 1);
((FetchItemQueues) fetchQueues).addFetchItem(fit);
outlinkCounter++;
}
}
// Overwrite the outlinks in ParseData with the normalized and
// filtered set
parseData.setOutlinks(outlinkList.toArray(new Outlink[outlinkList.size()]));
output.collect(
url,
new NutchWritable(
new ParseImpl(new ParseText(parse.getText()), parseData, parse.isCanonical())));
}
}
} catch (IOException e) {
if (LOG.isErrorEnabled()) {
LOG.error("fetcher caught:" + e.toString());
}
}
// return parse status if it exits
if (parseResult != null && !parseResult.isEmpty()) {
Parse p = parseResult.get(content.getUrl());
if (p != null) {
reporter.incrCounter(
"ParserStatus", ParseStatus.majorCodes[p.getData().getStatus().getMajorCode()], 1);
return p.getData().getStatus();
}
}
return null;
}
public ParseResult getParse(Content content) {
String mimeType = content.getContentType();
URL base;
try {
base = new URL(content.getBaseUrl());
} catch (MalformedURLException e) {
return new ParseStatus(e).getEmptyParseResult(content.getUrl(), getConf());
}
// get the right parser using the mime type as a clue
Parser parser = tikaConfig.getParser(MediaType.parse(mimeType));
byte[] raw = content.getContent();
if (parser == null) {
String message = "Can't retrieve Tika parser for mime-type " + mimeType;
LOG.error(message);
return new ParseStatus(ParseStatus.FAILED, message)
.getEmptyParseResult(content.getUrl(), getConf());
}
LOG.debug("Using Tika parser " + parser.getClass().getName() + " for mime-type " + mimeType);
Metadata tikamd = new Metadata();
HTMLDocumentImpl doc = new HTMLDocumentImpl();
doc.setErrorChecking(false);
DocumentFragment root = doc.createDocumentFragment();
DOMBuilder domhandler = new DOMBuilder(doc, root);
ParseContext context = new ParseContext();
try {
parser.parse(new ByteArrayInputStream(raw), domhandler, tikamd, context);
} catch (Exception e) {
LOG.error("Error parsing " + content.getUrl(), e);
return new ParseStatus(ParseStatus.FAILED, e.getMessage())
.getEmptyParseResult(content.getUrl(), getConf());
}
HTMLMetaTags metaTags = new HTMLMetaTags();
String text = "";
String title = "";
Outlink[] outlinks = new Outlink[0];
org.apache.nutch.metadata.Metadata nutchMetadata = new org.apache.nutch.metadata.Metadata();
// we have converted the sax events generated by Tika into a DOM object
// so we can now use the usual HTML resources from Nutch
// get meta directives
HTMLMetaProcessor.getMetaTags(metaTags, root, base);
if (LOG.isTraceEnabled()) {
LOG.trace("Meta tags for " + base + ": " + metaTags.toString());
}
// check meta directives
if (!metaTags.getNoIndex()) { // okay to index
StringBuffer sb = new StringBuffer();
if (LOG.isTraceEnabled()) {
LOG.trace("Getting text...");
}
utils.getText(sb, root); // extract text
text = sb.toString();
sb.setLength(0);
if (LOG.isTraceEnabled()) {
LOG.trace("Getting title...");
}
utils.getTitle(sb, root); // extract title
title = sb.toString().trim();
}
if (!metaTags.getNoFollow()) { // okay to follow links
ArrayList<Outlink> l = new ArrayList<Outlink>(); // extract outlinks
URL baseTag = utils.getBase(root);
if (LOG.isTraceEnabled()) {
LOG.trace("Getting links...");
}
utils.getOutlinks(baseTag != null ? baseTag : base, l, root);
outlinks = l.toArray(new Outlink[l.size()]);
if (LOG.isTraceEnabled()) {
LOG.trace("found " + outlinks.length + " outlinks in " + content.getUrl());
}
}
// populate Nutch metadata with Tika metadata
String[] TikaMDNames = tikamd.names();
for (String tikaMDName : TikaMDNames) {
if (tikaMDName.equalsIgnoreCase(Metadata.TITLE)) continue;
// TODO what if multivalued?
nutchMetadata.add(tikaMDName, tikamd.get(tikaMDName));
}
// no outlinks? try OutlinkExtractor e.g works for mime types where no
// explicit markup for anchors
if (outlinks.length == 0) {
outlinks = OutlinkExtractor.getOutlinks(text, getConf());
}
ParseStatus status = new ParseStatus(ParseStatus.SUCCESS);
if (metaTags.getRefresh()) {
status.setMinorCode(ParseStatus.SUCCESS_REDIRECT);
status.setArgs(
new String[] {
metaTags.getRefreshHref().toString(), Integer.toString(metaTags.getRefreshTime())
});
}
ParseData parseData =
new ParseData(status, title, outlinks, content.getMetadata(), nutchMetadata);
ParseResult parseResult =
ParseResult.createParseResult(content.getUrl(), new ParseImpl(text, parseData));
// run filters on parse
ParseResult filteredParse = this.htmlParseFilters.filter(content, parseResult, metaTags, root);
if (metaTags.getNoCache()) { // not okay to cache
for (Map.Entry<org.apache.hadoop.io.Text, Parse> entry : filteredParse)
entry.getValue().getData().getParseMeta().set(Nutch.CACHING_FORBIDDEN_KEY, cachingPolicy);
}
return filteredParse;
}
